Celtic have set their standards after getting the better of Italian side Lazio, ahead of the trip to Aberdeen, according to Fraser Forster.
That emphatic win kept the Celts at the top of Group E with seven points from three games.
The 31-year-old keeper, said: “It’s brilliant, we want as many games as possible and, obviously, it’s a quick turnaround for Sunday but you know we’ve got no choice.
“We just need to professional, recover well and get ready to play.
“It is another very important game, one that we need to win and the two results we have had this week, in the league and in the Europa League, that’s the standards we have set.
“We don’t want to drop below that so we want to go into Sunday’s game and get back on it.”
Looking back on his return to Paradise, he reflected: “When I found out there was a chance to come back here in the summer I couldn’t get back here quick enough.
“To get back playing at a place I really feel loved, appreciated and wanted, after a very tough 18 months, is really nice and that’s the reason I came back to play in games like that, in that stadium on those nights and everyone sees how special it is.”
Celtic skipper, Scott Brown, was impressed by Forster’s performance on Thursday night.
He said: “It was probably one of the best saves I’ve ever seen.
“But that’s why we brought him to the club, that’s why the manager believes in him and there was another save 10 minutes before that when he got his body in the way.
“We have three fantastic goalkeepers and they all make saves like that and that’s great competition for each other.”